Method for treating textile materials with a fluorocarbon resin



United States Patent O 3,540,923 METHOD FOR TREATING TEXTILE MATERIALS WITH A FLUOROCARBON RESIN Thomas F. Rozek, Bay City, Mich., assignor to The Dow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. Filed Dec. '15, 1967, Ser. No. 690,746

Int. Cl. B44d 1/09; B32b 27/04 US. Cl. 117-161 2 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a method for treating textile materials with a fluorocarbon resin, designed for application from aqueous systems, comprising precipitating from an aqueous emulsion or suspension containing the fluorocarbon resin, the resin by adding a ketone, such as acetone; separating the resin from the supernatant liquid; suspending or dissolving the resin in a chlorinated solvent; applying the so-prepared suspension or solution to a textile material; and, drying the fabric so as to maintain the organic fluorocarbon resin on the fabric to impart oil and water repellency.

BACKGROUND OF INVENTION For several years, the textile and fabric industry has been treating material with fluorocarbon base oil and water repellants such as, for example, Scotchgard (a proprietary product of 3M Company), Zepel (a proprietary product of the E. I. du Pont de Nemours Com pany). The early fluorocarbon base repellent chemicals were applied from aqueous emulsions, or dispersions. Recently, an apparatus and method for treating, among other things, textiles and fabrics with chemicals from solcent solutions has gained acceptance in the industry. The manufacturers of the treating chemicals have either modified their products or designed new products which are more compatible with the solvent systems of the new methods and useful in the new apparatus. These new compositions are expensive. It would, therefore, be advantageous if one could employ a cheaper source of fluorocarbon and obtain equivalent repellency.

BRIEF SUMMARY OF INVENTION In accordance with the present invention, a fluorocarbon such as described in US. Patents 2,841,573; 3,147,- 065; 3,147,066; 3,188,340; 3,198,754; 3,248,260; 3,256,- 230; 3,256,231; and 3,282,905; for example, in emulsified or dispersed systems as commercially available, is mixed with a sufiicient amount of a ketone, such as acetone, to precipitate the fluorocarbon resin. The precipitate freed of the supernatant liquor is then taken up in a chlorinated hydrocarbon in an amount sufficient to deposit under various application conditions 0.05 to 2% by weight of fluorocarbon resin solids to the textile material. The resulting mixture is applied to the textile material by padding, spraying or brushing the mixture onto the fabric to obtain properties of oil and water repellency. The so-wetted fabric is dried. The fluorocarbon resin remains on the textile While the major portion of the chlorinated solvent is dispersed to the drying atmosphere.

The fluorocarbons are generally available in aqueous systems as emulsions or dispersions of the following composition:

Percent by weight Fluorocarbon solids -38 Organic ketone 1030 Organic glycol 4-20 Water plus small percentage surface active agent Balance 3,540,923 Patented Nov. 17, 1970 ice The surprising part of the present invention is that a fluorocarbon specifically designed by the manufacturer and specifically incorporated into a concentrate form for use with water application can be put into a useful form in a chlorinated solvent, applied to textiles and impart the oil and water repellency at least equal to that obtained using the concentrate as designed by the manufacturer for use in organic solvents.

TEST METHODS 1) Oil Repellency: Hydrocarbon Resistance Test, AATCC 118-1966T (as published by the Proceedings of the American Association of Textile Chemists and Colorists, American Dyestulf Reporter, Feb. 13, 1967, pp. 43 and 44).

Apparatus and materials.--Test liquids prepared and numbered according to Table I TABLE I.STANDARD TEST LIQUIDS AATCC oil repellency Test specimens-One test specimen approximately 8 x 8 in. (20 x 20 cm.) is needed.

The test specimen should be conditioned for a minimum of four hours at 7012" F. (21:1 C.) ad 65i2% RH prior to testing.

Procedure-Place the test specimen flat on a smooth, horizontal surface.

Beginning with the lowest-numbered test liquid (AATCC Oil Repellency Rating No, l), carefully place a small drop (approximately V in. (5 mm.) diameter or 0.05 ml. volume) with the dropping bottle pipette on the test specimen in several locations. Observe the drop for 30 seconds, from approximately a 45 angle.

If no penetration or Wetting of the fabric at the liquidfabric interface and no wicking around the drop occurs, place a drop of the next higher-numbered test liquid at an adjacent site on the fabric and again observe for 30 seconds.

Continue this procedure until one of the test liquids shows obvious wetting of the fabric under or around the drop Within 30 seconds.

Evaluation.-The AATCC Oil Repellency Rating of a fabric is the highest-numbered test liquid which will not Wet the fabric within a period of 30 seconds. Wetting of the fabric is normally evidenced by a darkening of the fabric at the liquid-fabric interface. On black or dark shades, wetting can be detected by loss of sparkle within the drop.

Standard Spray Test: (Federal Specification CCC-T- 191b, Method 5526; AATCC Standard Test Method 22-1952).

Cut a 7" x 7" sample of the fabric to be tested and fasten it securely in the 6-inch metal hoop. Support the hoop on the stand of the tester so that the fabric is uppermost. Hoops holding twills, gabardines, piques or similar fabrics of ribbed construction should be placed on the stand so the ribs are diagonal to the flow of water running off the fabric.

Pour 250 cc. of water at (27 C.)i2 F. from a cup or other container into the funnel of the tester, and allow it to spray onto the fabric.

On completion of the spraying, hold one edge of the hoop and tap the opposite edge once against a solid object (the fabric should face this object), then rotate the hoop 180 and tap once more at the point previously held.

After tapping, compare the spotted or wetted pattern with the standards reproduced in the attached chart. Assign the fabric a rating corresponding to the nearest standard. Do not interpolate a rating between the standards.

Disregard any passage of water through a light, porous fabric, such as a voile.

(2) Oleophobic TestAs used prior to AATCC 118-1966-T: This is a test for determining the resistance of textiles to wetting by organic liquids. The test is useful for controlling the uniformity of textile finishing agents and finished fabrics from lot to lot. It indicates, to a degree, the resistance of textiles to oily stains.

Drops of fluid hydrocarbons of varying surface tension are placed, without impact, on the fabric surface and the extent of surface wetting is determined visually.

Eight ground glass, 60 ml. eye dropper bottles are used for containing the liquid hydrocarbons. The eye dropper must be equipped with a solvent resistant bulb such as one made of Neoprene. The hydrocarbons (except the Nujol" are petroleum solvents available from Matheson, Coleman & Bell, East Rutherford, NJ. Other sources of the solvents are undoubtedly satisfactory but have not yet been evaluated. The solvents and catalog designations are as follows.

Solvent: Matheson, Coleman & Bell number n-Heptane HX 80 n-Octane OX 60 n-Decane DX 30 n-Dodecane DX 2420 n-Tetradecane TX 220 n-Hexadecane HX 205 Cut a 2" x 8" conditioned (at least four hours at 65i2% RH. and 70 (21 C.):2 F.) sample of the fabric to be tested and place it in a horizontal position face up on white blotting paper of the quality used in the AATCC Dynamic Absorption Test for water repellents.

Start with the hydrocarbon for the highest oleophobic rating. Place at least two drops from an eye dropper, about one inch apart, on the fabric without impact. Within 10 seconds, determine wetting or no wetting of the fabric surface by visual inspection with lighting at an angle. Wetting is determined by the absence of light reflectance at the fabric-drop interface. Repeat the test With the hydrocarbon for the next rating until wetting (or no wetting) occurs. Assign a rating corresponding to the hydrocarbon with the highest rating that does not wet the fabric surface under the drop and does not wet around the drop as indicated by wicking. Do not remove the drop to observe wetting because pressures involved may influence the rating. Mount light-weight or porous fabrics on an embroidery hoop to avoid capillary elfects from the blotting paper.

In rating black on dark-colored fabrics, it is sometimes ditficult to observe a true loss of sparkle at the liquidfabric interface. In such cases, it is suggested that an estimation be made of the contact angle by observing the drop from a very low angle. The fabric should then be assigned a rating corresponding to the highest-numbered hydrocarbon which fails to lower the contact angle below 90 degrees.

Hydrocarbon Oleophobic rating number 1 n-Heptane 9 n-Octane 8 n-Decane 7 Nujol is the Plough, Inc. trademark for a refined mineral oil sold by retail drugstores.

4 Hydrocarbon Oleophobic rating number 1 n-Dodecane 6 n-Tetradecane 5 50 ml. Nujol+50 ml. n-Hexadecane 4 75 ml. Nujol+25 ml. n-Hexadecane 3 Nujol 2 (Nujol Wets) 0 1 Hydrocarbon with the highest rating number that does not wet the fabric.

(3) Another Oil Repellency Test is based on the different penetrating properties of two hydrocarbon liquids, mineral oil (Nujol) and n-heptane. Mixtures of these two liquids are miscible in all proportions and show penetrating properties proportional to the n-heptane content of the mixture.

The oil repellency rating numbers were chosen to correspond with the AATCC Standard Spray Ratings which were in use prior to AATCC 118-1967(t) for testing water repellent finishes. The Nujol-heptane proportions for each rating were selected so as to give oily stain resistance somewhat comparable to the water-borne stain resistance corresponding to each of the Standard Spray Test Ratings.

TABLE.COMPOSITION OF LIQUID MIXTURES FOR THE OIL REPELLENCY TEST Oil repellency Percent Percent rating mineral oil 1 n-heptane 2 l Nujol (Plough Inc.) Saybolt viscosity 360/390 at 100 F. Specific gravity .880/.900 at 60 F. Percent by volume at 20 C.

2 Heptane (Matheson, Coleman & Bell) B.P. 9899 0. Percent by voltime at 20 C.

3 No holdout to mineral oil.

EXAMPLE 1 Two liters of an aqueous emulsion of a commercial stain repellent containing ca. 28% by weight of an organic fluorocarbon resin (analytically determined to be predominantly 1,1,2 trichloro 1,2,2 trifluoro-ethane), 8% ethylene glycol, 12% acetone, and the balance water, was mixed with 2 liters of acetone. An off-white pricipitate formed, was allowed to settle, the supernatant liquor decanted and the precipitate taken up in sufficient stabilized 1,1,1-trichloroethane to yield a 28% solids solution. This solution was further diluted with 1,1,l-trichloroethane to provide a 4.3% solution of fluorocarbon resin concentrate in 1,1,1-trichloroethane, and employed to treat a 14 ounce wool fabric, a tricot and an 11 ounce rayon-acetate blend fabric by spraying the solution onto the fabric under a pressure of 12 p.s.i. while moving the fabric through the spray zone at a rate of 22 yards per minute. The employment of a 4.3% solution of the concentrate will provide a deposition of 0.3 percent solids by weight of fabric. The so-treated fabrics were dried. In this manner, the major portion of the chlorinated hydrocarbon solvent was removed leaving the fluorocarbon resin on the fabric. The standard test for oil and stain repellancy was run. The face of each fabric treated was found to have an oil repellency rating of 5. AATCC 118-1966T.

EXAMPLE 2 In a similar manner as set forth in Example 1, 3 gallons of solution were prepared. A 14-16 ounce upholstery fabric was treated with the solution by spraying the solution onto the fabric from 15 nozzles under 25 p.s.i. pressure at a line speed of 13 yds/min, to impart a calculated 0.3% solids on fabric. The so-sprayed fabric was dried, then tested for oil repellency. The face of the fabric exhibited a rating of on the oil test.

EXAMPLE 3 In order to compare the results obtained by the technique of the present commercial solvent based solution treating agent containing fluorocarbon in 1,1,l-trichloroethane and stabilizers was diluted to a concentration to provide a calculated 0.3% fluorocarbon solids deposition on the fabric when applied under a controlled condition. In the instant case, the solution was sprayed onto the same fabric (as in Example 2) at yds./min. under 15 p.s.i. pressure from 15 nozzles. The fabric after drying rated 5 on oil repellency.

In a similar manner, another commercial solvent based fluorocarbon stain, oil and water repellent solution was diluted in 1,1,1-trichloroethane and stabilizers to give 0.4% fluorocarbon solids by weight retention on the fabric. This solution was sprayed in the same manner as 3 above and dried. The oil rating was 4.

EXAMPLE 4 A series of tests were run employing a composition prepared in the manner of Example 1, e.g., a solution prepared by incorporating an acetone-precipitated fluorocarbon (from its aqueous composition) into 1,1,l-trichloroethane. The instant solution was sprayed from 15 nozzles under 13 p.s.i. onto six different commercially available fabrics (blends of natural and synthetic fibers) obtained from various mills at a rate of about 22 yds./ min. This treatment provided a deposit of resin solids on the fabric of about 0.3% by weight. The fabrics were dried and tested for oil repellency.

Fabric weight: Rating fabric face 1 1 Oil repellency test.

I claim:

kanesulfonamido alkylenemonocarboxylic acids,

(b) quaternized perfluoroalkyl N halomethyl carboxylic amides,

(c) quaternized perfluoroalkane sulfonamido N- halomethyl carboxylic amides,

(d) polyfluoroalkanamidoalkyl phosphates,

(e) aziridinyl derivatives of highly fluorinated organic monocarboxylic acids,

(f) interpolymers of N-methylol acrylamides with fluoroalkyl ester.

(g) polymers of a vinyl fluoro aliphatic compound and a vinyl compound,

(h) an ester having the formula i I H-C-CHz H or polymer having the recurring unit CH3 l-CH2 and,

(4) the balance water, recovering the solid fluorocarbon resin in said emulsion and dissolving said resin in a chlorinated hydrocarbon having from 1 to 2 carbon atoms and from 2 to 4 chlorine atoms per molecule, treating fabric with said diluted solution, and drying the treated fabric so as to leave the resin on the fabric thereby imparting the desired repellency.

2. In the method of claim 1 wherein said fluorocarbon solids are first dissolved or dispersed in said solvent in a concentration of from about 2 to by weight and thereafter diluting said mixture to a concentration to provide an amount of said solids in said solvent sufficient to deposit from 0.05 to 2% resin solids onto said fabric.

References Cited UNITED STATES PATENTS 6/1953 Ahlbrecht et a1. 260-835 8/ 1957 Ahlbrecht et al.

U.S. Cl. X.R. 

